Injection needle guide



Dec. 5, 1967 2 Sheets-Sheet 1 Filed March 1, 1965 S C Y R OM M T R R NF0 E. v w W D A R A W 0 H VI 8 NBA,

NM I H N Nm Dec. 5, 1967 I H. R. FRANCIS INJECTION NEEDLE GUIDE 2Sheets-Sheet 2 Filed March 1, 1965 I NVENTOR.

HOWARD R. FRANCIS ATTORNEY United States Patent 3,356,089 INJECTIONNEEDLE GUIDE Howard R. Francis, Provo, Utah 84601 Filed Mar. 1, 1965,Ser. No. 436,004 5 Claims. (Cl. 128-221) ABSTRACT OF THE DISCLOSURE Ahypodermic unit for use in relatively inaccessible locations, having aneedle sheath attached to a lighttransmitting cylindrical outer barrelwith external graduations, and an intermediate medication barrel with aninterior plunger and having a long needle joined to the forward end ofthe medication barrel and generally closely surrounded by the sheath sothat controlled advancing and retracting of the medication barrelselected distances within the outer barrel by reference to thegraduations on the outer barrel will (a) extend the needle tip outsidethe sheath for selected depth penetration of a relatively inaccessiblelocation of a patients body and (b) dispose the needle tip within thesheath, respectively. Once the needle tip has penetrated the body,advancing of the plunger a selected distance relative to the medicationbarrel will expel a known quantity of medication into the patient.

This invention relates in general to certain new and useful improvementsin hypodermic syringes and, more particularly, to hypodermic syringesadapted for use in paracervical or pudendal anesthesia, paracentesis, orsimilar surgical procedures.

The conventional type of hypodermic syringe usually consists of abarrel, piston-like plunger, and a hypodermic needle, the length ofwhich ordinarily ranges from one to three inches. Such needles areusually inserted into the patients upper arm or buttocks and, prior toinsertion, the area of the skin surrounding the place of penetrationwill be sponged off with alcohol or other suitable antiseptics to renderthe area reasonably sterile. Inasmuch as the area is relativelyaccessible and the manipulative techniques are conventional, there isvery little likelihood that the doctor, nurse, or medical technicianusing such a hypodermic syringe will violate asepsis. There are,however, a number of surgical situations in which it is highly desirableto use a hypodermic syringe having an extremely long needle forinsertion into relatively inaccessible areas of the patients body.

For example, in paracervical or pudendal anesthesia, a local anestheticis injected at selected locations around the patients cervix. This typeof anesthesia is used by many obstetricians to avoid the liability of ageneral anesthetic which tends to reduce the cooperative activity of thepatient in bearing down during delivery and also is felt by some to besomewhat dangerous to the fetus. The administration of paracervicalanesthesia by means of a conventional hypodermic syringe is quitediflicult for a number of reasons.

In the first place, when the patient is in delivery position with herlegs supported in obstetrical crutches, the entire cervical region isnot particularly accessible for the application of a conventionalhypodermic syringe having a needle of the usual length. Moreover,because of discomfort associated with labor the patient often hasdifiiculty holding still and, accordingly, it is impossible to attainany degree of precision in the insertion of the hypodermic needle intothe tissue surrounding the cervix. Furthermore, it is relatively easyfor an unprotected needle to penetrate the vaginal wall or even fetaltissue in the attempt to approach the site of intended injection.Finally, an obstetrician, under circumstances of actual delivery,

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is using surgical gloves which very often are punctured by thehypodermic needle if it slips or is otherwise misdirected, therebycausing contamination.

In the administration of paracervical anesthesia, it is also extremelydesirable for the obstetrician to know, within reasonable limits ofaccuracy, the depth to which the needle is inserted, but this cannot bereadily estimated when using conventional hypodermic syringes. Asomewhat similar problem is encountered in paracentesis, which procedureinvolves a surgical puncture of an anatomical cavity. In suchprocedures, it is extremely desirable to know the depth to which theneedle has entered into the cavity. Furthermore, for purposes ofparacervical anesthesia, paracentesis, or for any other surgicalprocedure requiring the use of a long hypodermic needle, it is alsodesirable to maintain the needle within an aseptic sheath or enclosureuntil the actual moment of puncture.

It is, therefore, the primary object of the present invention to providea novel hypodermic syringe having a long sheathed needle which can bemaintained within the sheath until the actual moment of puncture andthen manually projected from the sheath into the patients flesh in amanner which maintains a maximum degree of asepsis.

It is another object of the present invention to provide a hypodermicsyringe of the type stated having a relatively long needle Which can beinserted into the patients flesh to a known and measured depth.

It is a further object of the present invention to provide a hypodermicsyringe of the type stated which can be constructed of relativelyinexpensive materials without sacrifice of efficiency or utility, sothat the entire needle can be considered as disposable or, in otherworths, used once and then discarded.

With the above and other objects in view, my invention resides in thenovel features of form, construction, arrangement, and combination ofparts presently described and pointed out in the claims.

In the accompanying drawings:

FIG. 1 is a side elevational view of a hypodermic syringe constructed inaccordance with and embodying the present invention;

FIG. 2 is a longitudinal sectional view taken along line 22 of FIG. 1;

FIGS. 3, 4, 5, and 6 are transverse sectional views taken along lines3-3, 44, 55, and 66, respectively, of FIG. 1;

FIG. 7 is a side elevational view of the sheath and graduated outerbarrel forming a part of the present invention;

FIG. 8 is an exploded side elevational view of the barrel and needleforming a part of the present invention;

FIG. 9 is an exploded side elevational view of the plunger forming apart of the present invention;

FIG. 10 is a transverse sectional view taken along line 1010 of FIG. 9;and

FIG. '11 is a fragmentary sectional view taken along line 11-11 of FIG.10.

Referring now in more detail and by reference characters to thedrawings, which illustrate a preferred embodiment of the presentinvention, A designates a hypodermic syringe consisting of four majorparts or components, namely, a graduated outer barrel 1, a medicationbarrel or cylinder 2, a needle 3, and a piston-like plunger 4.Preferably the outer barrel 1, cylinder 2, and plunger 4 are molded froma transparent synthetic resin, such as, for example, a polystrene,polyvinyl, or methylmethacrylate resin. The actual molding or othermethods by which these parts can be fabricated are conventional and,therefore, are not described herein in detail. It is sufiicient forpresent purposes to point out that the plastic components may preferablybe made by injection molding and, where it is necessary for one plasticpart J to be joined rigidly to another, conventional adhesives, wellknown to the art, may be employed.

The outer barrel 1 integrally includes a tubular section 5 which is openat one end and, at such end, is provided with an external annular collar6. Internally, the tubular section 5 is as smooth and preciselycylindrical as possible. This can be readily achieved without undueexpense for manufacturing cost by the use of well polished,precisely-machined molding dies constructed in accordance withwell-known die-making practice. At its other or so-called closed end,the tubular section 5 is integrally provided with a frusto-conical endwall 9, which is, in turn, integrally joined at its forward end(reference being made to the left-hand side of FIG. 1) with a coaxialtubular extension 8. Integrally joined to the forward end of the tubularextension 8 is a tapered section 7 which extends forwardly and mergesinto an elongated tubular sheath 10, integrally provided at its forwardend with an enlarged spherical bulb 11 having a smallbored coaxialaperture 12 formed in its forwardmost portion. As will be seen byreference to FIGS. 1 and 7, the tubular section 5, the tubular extension8, the tubular sheath 10, and the aperture 12 are all in coaxialalignment along a common centerline which is the longitudinal centerlineof the hypodermic syringe A.

Adhesively or otherwise rigidly secured within the tapered section 7 andprojecting coaxially into the rear end of the tubular sheath is a guidesleeve 13 integrally consisting of a somewhat conical rear-end portion14 and forward extension portion 15 which terminates in a diametricallyreduced tip 16. The guide sleeve 13 is preferably molded of a syntheticresin or so-called plastic which is the same as the material used forthe other plastic parts of the hypodermic syringe A and is formed with atubular bor 17 which is also coaxial with the longitudinal centerline ofthe hypodermic syringe A and is of substantially the same internaldiametral size as the aperture 12.

The cylinder 2 consists of a tubular member 18 which is formed of atransparent plastic such as one of the aforementioned synthetic resinsand is internally provided with a cylindrical surface 19. At its rearend, the tubular member 18 is completely open and adjacent to its rearend, is externally provided with two diametrically opposite 'U-shapedfinger loops 20, 21, which are cemented or otherwise rigidly securedthereto. At its other or forward end, the tubular member 18 is providedwith a circular plug-shaped closure member 22 which has an annular skirt23 sized for snug-fitting disposition within the forward end of thetubular member 18. The skirt 23 is marginally joined to the outerperiphery of a forwardly projecting conical end wall 24, which, in turn,integrally merges into a forwardly projecting externally taperedhub-receiving fitting 25 having an axial bore 26 that merges at itsrearward end into the internally tapered face of the conical end wall24. Integrally formed with, and projecting annularly outwardly aroundthe forward end of the skirt 23, is a collar 27, the external diametralsize of which is substantially equal to the external diametral size ofthe tubular member 18. Provided for snug-fitting disposition externallyaround the skirt 23 is an O-ring 28 which is slightly larger in externaldiametral size than the external diametral size of the collar 27 andtubular member 18. Thus, when the O-ring 28 is slipped over the skirt23, and the latter is inserted into the forward end of the tubularmember 18, the O-ring 28 will fit snugly and slidably within theinterior surface of the tubular section 5 of the outer barrel 1, in themanner of a piston ring. It will, of course, be evident that theexternal surface of the skirt 23 is tightly cemented to the forward endof the tubular member 18 so as to form a liquidtight pressure-resistantseal therewith, all as best seen in FIG. 2.

The needle 3 integrally includes a steel hub-member 29 having aninternally tapered socket 30 adapted to fit seatingly upon the taperedsurface of the fitting 25. At its forward end, the hub 29 is providedwith a diametrally reduced coaxial tubular extension 31 which rigidlyembraces the rear end of an elongated steel cannula 32, the forward endof which is beveled and sharpened to facilitate penetration of theflesh. Moreover, the cannula 32 is of such external diametral size thatit will fit snugly, but, nevertheless, slidably, through the bores 12and 16, substantially as shown in FIG. 2.

The plunger 4 includes an elongated cylindrical member 33 having anexternal diametral size substantially equal to the internal diametralsize of the cylindrical surface 19 so as to fit snugly and slidablytherein. The tubular member 33 is also preferably fabricated of atransparent plastic material, such as one of the previously mentionedsynthetic resins, and is integrally provided at its rearward end with adiametrally enlarged annular collar 34 provided with a pair ofdiametrally opposite rectangular ears 35, 36, having rearwardly openingrectilinear recesses 37, 38, for snugly accommodating the opposite endsof a diametrally extending cross-bar 39 which is integrally provided onits rearward face with a rearwardly projecting finger-loop 40. Thecross-bar 39 is tightly cemented or otherwise rigidly secured at itsends in the recesses 37, 38, so that the finger-loop 40 may be utilizedfor manipulating the plunger 4.

At its forward end, the plunger 4 is provided with a diametrally reducedannular shoulder 41, the interior surface of which defines a diametrallyreduced opening 42. Provided for disposition within the forward end ofthe tubular member 33 is a piston-forming rubber plug 43 having aforward conical end 44 which is tapered to the same angle as the taperedskirt 23 of the closure member 22 which forms a part of the cylinder 2.

The conical end 44 terminates in a diametrally enlarged annular ring orshoulder 45 which is, in turn, connected by means of a diametrallyreduced cylindrical portion 46 and a second annular ring or shoulder 47,the rings or shoulders 45, 47, being of such external diametral size asto form a piston-like sliding seal against the cylindrical surface 19 ofthe cylinder 2 when the plunger 4 is operatively inserted therein. Atits rearward end, the plug 43 includes a diametrally reduced skirt 48,the external diametral size of which is substantially equal to theinternal. diametral size of the opening 42. At its rearward end, theskirt 48 is provided with a collar-portion 49, the external diametralsize of which is substantially equal to the inter-- nal diametral sizeof the tubular member 33. The axial! length of the skirt 48 is veryslightly smaller than the axial' tions of the plug 43 are insertedthrough the opening 42,.

the collar-portion 49 will seat snugly against the interiorfaces thereofand hold the plug 43 firmly in operative posi-- tion at the forward endof the tubular member 33.

It will be noted by reference to FIGS. 1 and 7, that the: tubularsection 5 of the outer barrel 1 is provided with a. series ofgraduations and half-graduations respectively indicating centimeters andhalf-centimeters of axial distance. As shown, the scale of graduationsencompasses a distance of four centimeters. The fourth full-centimetergraduation is coincident with the line of juncture between thefrusto-conical end wall 9 and the forward end of the tubular section 5.It will, of course, be understood in this connection, that the number ofgraduations and the distances therebetween can be varied to reflect anyselected scale and to measure off any desired distance withinappropriate limits. Approximately 1.5 to 2.0 cm. have been found to beparticularly suitable for hypodermic syringes which are to be used forparacervical anesthesia. On the other hand, hypodermic syringes whichare intended for paracentesis will possibly require up to 4 cm. as areprovided for in the present model described. Other possible uses mightrequire even deeper penetration in which case the outer barrel 1 andcannula 32 will be correspondingly longer also.

The cannula 32 is of such axial length that, when the forward annularmargin end of the cylinder 2 is shifted to the zero calibration, thecannula 32 will be entirely withdrawn into the sheath and the pointedend thereof will be withdrawn into the bore 12 of the spherical bulb 11.On the other hand, when the cylinder 2 is pushed forwardly through theouter barrel 1 until the forward margin end is at its forwardmostposition, that is to say, the position in line with the four centimetergraduation on the scale, the pointed end of the cannula 32 will extendfour centimeters beyond the aperture 12.

Prior to actual use, the cylinder 2, with the needle 3 operativelyattached, is withdrawn entirely from the outer barrel 1 and filled witha suitable quantity of any desired local anesthetic. This may be done inthe conventional manner of filling any hypodermic syringe. The cylinder2, with its associated needle 3 and plunger 4, is then reinserted intothe outer barrel 1 until the forward margin end is aligned with the zerocalibration scale. Thereupon, the obstetrician placed the spherical bulb11 at about an 8:00 oclock position to one side of the cervix. Since thesharp point of the cannula 32 is not exposed, there is virtually nopossibility of violating asepsis in this procedure and the obstetriciandoes not need to concern himself with the danger of puncturing eitherhis glove or finger when he is holding the flesh of the patient in firmstationary position preparatory to emplacing the pointed end of thecannula 32. After proper placement adjacent to'the cervix, the cannulais extended about one and onehalf centimeters to 2 cm. by forcing thecylinder 2 forwardly within the outer barrel 1 by that distance asmeasured along the scale of calibrations. About 6-10 cubic centimetersof an anesthetic are then injected. The hypodermic syringe A is thenwithdrawn and, after about one or two contractions of the uterus, thesame procedure is followed on the other side of the cervix at about 3:00to 4:00 oclock position. Should an episiotomy be required for easydelivery of the fetus, the cannula 32 can be extended to whatever lengthis necessary and anesthetic can be injected into the Wall of the vaginain the appropriate positions to anesthetize the pudendal nerve.

By reason of the fact that the hypodermic syringe A is constructed ofrelatively inexpensive plastic components, it can be manufactured veryinexpensively and, thus, may be discarded after one use. The hypodermicsyringe A, constructed in accordance with the present invention,therefore, becomes a disposable syringe which can be sterile-packed attime of manufacture, so that the doctor or hospital is relieved of thenecessity of sterilizing the hypodermic syringe A at or prior to time ofactual use. This, obviously, results in material economies, both interms of time and materials. As a matter of fact, actual experience hasshown that precision-made glass syringes of conventional design arehighly susceptible to breakage and survive only a small number of actualuses. This fact, coupled with the high initial cost and the substantialexpenses involved in cleaning and sterilizing such syringes after eachusage, clearly establishes that disposable hypodermic syringesconstructed in accordance with the present invention are much moreeconomical.

It should be understood that changes and modifications in the form,construction, arrangement, and combination of the several parts of thehypodermic syringes may be made and substituted for those herein shownand described without departing from the nature and principle of myinvention.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A hypodermic syringe comprising a hollow lighttransmitting smoothbore outer barrel open at one end, a cylinder adapted to receive aplunger and having a smooth exterior surface slideably mounted in thebarrel through and extending beyond the open end of the barrel andvisible through the wall of the barrel, means interposed between thebore of the barrel and the exterior surface of the cylinder tofrictionally restrain the cylinder in any selected one of a number ofincrementally distinct positions relative to the barrel, a longhypodermic needle sheath having inside and outside diameters eachseveral times smaller than the inside and outside diameters of thebarrel, respectively, and being mounted at one end thereof on a secondgenerally closed end of the barrel, a long needle mounted on the forwardend of the cylinder and always extending through and well beyond thesmall opening and loosely extending through at least almost the entirelength of the enclosing needle sheath, said barrel carrying graduationsso that the cylinder may be selectively positioned within the barrelrelative to the barrel graduations (a) for locating the needle tipslightly within the sheath at the leading end of the sheath toaccommodate precise location and removal of the leading end of thesheath adjacent the body of a patient prior to and followingpenetration, respectively, and (b) for advancing the needle tip from theselectively positioned leading end of the sheath a distancecorresponding to the barrel graduations caused to be traversed by thecylinder to inject only the needle tip to a desired depth into thepatient at said precise location.

2. A syringe as defined in claim 1 wherein the leading end of the needlesheath is bulbous in configuration.

3. A syringe as defined in claim 1 wherein said frictionally restrainingmeans comprises an O-ring to accommodate relative sliding movement ofthe barrel and the cylinder and to frictionally maintain any selectedrelative position of the barrel and the cylinder.

4. A syringe as defined in claim 1 further comprising a guide sleevedisposed in the vicinity of the small opening to snugly though slideablyreceive and guide the needle to accommodate generally axial to and fromovement of the needle relative to the sheath in spaced relationthereto.

5. A syringe as defined in claim 1 wherein the trailing end of thecylinder has two opposed finger-grips each having front and backabutment surfaces for forcibly advancing and retracting the cylinderwithin the barrel as desired.

References Cited UNITED STATES PATENTS 561,059 5/ 1896 Mitchell 128-2182,571,653 10/ 1951 Bastien 1282l8 2,876,770 3/1959 White 1282152,922,420 l/ 1960 Cheng 128-221 2,923,295 2/1960 Guerriero 128-2153,028,862 4/1962 Prater 128218 FOREIGN PATENTS 532,170 10/1954 Belgium.

RICHARD A. GAUDET, Primary Examiner.

D, L. BAKER, Assistant Examiner,

1. A HYPODERMIC SYRINGE COMPRISING A HOLLOW LIGHTTRANSMITTING SMOOTHBORE OUTER BARREL OPEN AT ONE END, A CYLINDER ADAPTED TO RECEIVE APLUNGER AND HAVING A SMOOTH EXTERIOR SURFACE SLIDEABLY MOUNTED IN THEBARREL THROUGH AND EXTENDING BEYOND THE OPEN END OF THE BARREL ANDVISIBLE THROUGH THE WALL OF THE BARREL, MEANS INTERPOSED BETWEEN THEBORE OF THE BARREL AND THE EXTERIOR SURFACE OF THE CYLINDER TOFRICTIONALLY RESTRAIN THE CYLINDER IN ANY SELECTED ONE OF A NUMBER OFINCREMENTALLY DISTINCT POSITIONS RELATIVE TO THE BARREL, A LONGHYPODERMIC NEEDLE SHEATH HAVING INSIDE AND OUTSIDE DIAMETERS EACHSEVERAL TIMES SMALLER THAN THE INSIDE AND OUTSIDE DIAMETERS OF THEBARREL, RESPECTIVELY, AND BEING MOUNTED AT ONE END THEREOF AN A SECONDGENERALLY CLOSED END OF THE BARREL, A LONG NEEDLE MOUNTED ON THE FORWARDEND O F THE CYLINDER AND ALWAYS EXTENDING THROUGH AND WELL BEYOND THESMALL OPENING AND LOOSELY EXTENDING THROUGH AT LEAST ALMOST THE ENTIRELENGTH OF THE ENCLOSING NEEDLE SHEATH, SAID BARREL CARRYING GRADUATIONSSO THAT THE CYLINDER MAY BE SELECTIVE LY POSITIONED WITHIN THE BARRELRELATIVE TO THE BARREL TRADUATIONS (A) FOR LOCATING THE NEEDLE TIPSLIGHTLY WITHIN THE SHEATH AT THE LEADING END OF THE SHEATH TOACCOMMODATE PRECISE LOCATION AND REMOVAL OF THE LEADING END OF THESHEATH ADJACENT THE BODY OF A PATIENT PRIOR TO AND FOLLOWINGPENETRATION, RESPECTIVELY, AND (B) FOR ADVANCING THE NEEDLE TIP FROM THESELECTIVELY POSITIONED LEADING END OF THE SHEATH A DISTANCECORRESPONDING TO THE BARREL GRADUATIONS CAUSED TO BE TRAVERSED BY THECYLINDER TO INJECT ONLY THE NEEDLE TIP TO A DESIRED DEPTH INTO THEPATIENT AT SAID PRECISE LOCATION.